Formula E’s third season sees new powertrains, steering wheels, bodywork and much more, as Scarbs finds out.
Tech, tech, tech: we love it. Blueprints has been exploring the technical aspects of the FIA Formula E series since season one and we have lots more in store over the forthcoming season. It may only be the electric sport’s third year but no one is standing still. Season three sees new powertrains, new technology, new drivers and new circuits. It’s going to be one hell of a ride. Let’s get started.
- Powertrains Just about every team in the paddock has pitched up with a new powertrain. Some of these are little more than tweaked versions of their season two units, such as at Renault and ABT; others are similar in concept but repackaged, such as at NextEV (the only team in season three to run twin motors); and others are wildly, wildly different to their earlier efforts (such as Mahindra, DS Virgin Racing and Venturi). Those changes are substantial: DSVR has dropped its twin motor solution for a single motor effort, for example, and Mahindra’s M3Electro powertrain features more than 300 new components. There’s only one customer team on the grid this season, which is Techeetah (with Renault powertrains). Given that permitted energy and power output levels remain the same as in season two, teams have been chasing gains in efficiency and in packaging (how the powertrain sits within the car and its effects on handling characteristics). “Testing was 50% about reliability, 30% about powertrain performance optimisation and 20% about chassis and driver,” says Vin Patel, chief engineer at Mahindra Racing, about the team’s development process over the summer. “For us at Mahindra Racing, Hong Kong confirmed what we expected to see from private testing and Donington Park and there are incremental gains to be made throughout the season as we gain confidence in pushing the limits of our new powertrain further.”
- Battery The race battery, revamped for season three, continues to be supplied by Williams Advanced Engineering. Teams are permitted to use 28kWh battery energy in each car during the race, with race mode set at 170kW power output and qualifying at 200kW. The battery itself remains a top secret bit of kit, weighing in at around 320kg, complete with a trick carbon fibre safety casing. “Operating temperatures are slightly different but everything is largely as it was in season two, including recharging procedures,” Patel explains.
- More regen The rate at which teams are allowed to capture energy through regenerative braking (which is only available via the rear axle) has skyrocketed from 100kW in season two to 150kW in season three. “This has included motor and gearbox design, as we need to ensure nothing is close to failure at the upper limits of regen,” says Patel. This brings to mind all those broken gearboxes in season one, when the standard parts supplied to teams couldn’t cope with the sudden reverse loads introduced with regen, something pretty unique in racing to Formula E. The increased regen limit could actually make the cars easier to drive, Patel says: “Because the hydraulic braking system is fixed, not dynamic like in other sports, the 100kW cap contributed to an inconsistent brake balance in season two. With 150kW now available, this should balance the car better.”
- Steering wheel A new XAP unit for season three is now fully configurable. “The new unit sports six rear paddles, six rotary controls, 10 buttons, LED warning lights and a larger colour LCD dash display,” according to a recent Current E piece. “The wheel has customisable menus for the team and driver to access the car’s control systems, far exceeding the mere five pages in the previous version. Above the dash is a row of LED lights, which were used for to indicate when to change gear in the first season configuration. Also making an appearing is a triangular cluster of three LEDs; these are the FIA warning light system, which light a LED to match the coloured flags being waved trackside by marshals.” In terms of tech, the new steering wheel is thought to be more sophisticated than a GP2 car but not quite on a par yet with those used in F1 or the LMP1 class of WEC. How teams set up their new steering wheels is utterly confidential. “Teams and drivers now have access to far more tools,” says Patel. “There are teething issues to work through, which I think you could see in Hong Kong with some other teams.”
- Front wing A futuristic, sinuous new part which effectively adds a top plane, connected to the sidepods. New turning vanes feature at the outside edges of the sidepods. The new unit is around 3kg heavier than the old one and has been added primarily for aesthetic effect. “There’s slightly less downforce than the old wing but balancing the car is pretty simple,” says Patel. “One big advantage is that it is a much stiffer component, so we should see less damage in close-quarters wheel to wheel action, of which there is a lot in Formula E.”
- New tyres Michelin has introduced a new version of its 18 inch treaded all-weather tyre for season three. The rubber rings have provided good, reliable and predictable grip levels for the drivers for the past two seasons, and the new tyres appear to be even better. There is some debate about their use within the paddock, with some teams asserting that the cars could be five seconds a lap faster if conventional slick tyres were used. Still, these tyres are far more relevant to road cars and help to underline Formula E’s direct links to mainstream automotive development.